It shows up on the API test no problem with prime, I hear Coral sand IS NOT to be used with plants though or so I was told when I bought mine.
My plants came today, I will upload pictures later or tomorrow got about 40 plants lol.
6 x Amazon Swords
10 x Canadian Pondweed
10 x some other weed
5 x some other weed
3 x water sprites
3 x some other plant
If there's anything I could do to help then I will try, it would be a bit of a drive like though. If your plants take a turn for the worst and assuming mine don't either I'll give you a bunch of them. Theres no way I'm going to use them all, probably 3/4 max of the swords.
I think you should find out if Bi-carb will hurt your plants, and add a little bit of it. Enough to raise the pH and then when the stats return to normal drain the tank down to your plant level and then fill it up and drain it again. Ignore water temperature for the first refill and repeat with proper temperature matching. You will mostly dilute it.
I honestly think it's some of this plant product that has effected your pH although I personally think if you can get the stats pretty close to 0.0 you should add some fish after a big water change. Our pH has been pretty stable at 7.6 since we added the fish although I am expecting it to drop over some time when the Nitrate concentrations goes up.
I do feel like a lot of the effort waiting for 0.0 at 4ppm is wasted when I've only added 30-40% of the fish stock. However I do feel A LOT better about knowing our fish are in great water conditions. It seems perfect at the moment compared to our previous attempt at fish keeping. So you could always try get the water conditions close and then add your pair of Rams. I hear they are hardy but I also hear they're not hardy! So not sure what to think about that one, though 2 rams isn't 50% stocking for you?
Maybe Waterdrop or OldMan can help you on this one about whether adding the fish which MAY be exposed to very small quantities of Ammonia/Nitrite would be safe. I can imagine the filter would either cope with it easily or take a small time to catch up with it.
So my vote is your give it a few days and add your pair of rams.
COME ON MEXICO